The Si7818DN from Vishay is a MOSFET with Continous Drain Current 3.4 A, Drain Source Resistance 112 to 142 Milliohm, Drain Source Breakdown Voltage 150 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 1 to 3 V. Tags: Surface Mount. More details for Si7818DN can be seen below.